Tail skid for aircraft



R. K. PIERSON ET AL..

TAIL SKID FOR AIRCRAFT Filed June` 2l Patented @et 3D, i923.

entre@ stares amarante HAW PIERSON AND THOMAS SMITH D'UNG, 0Fl WESTMINSTER,

LONDON, ENGLAND, ASSIGNORS T0 VICKERS LIMITED, 0F WESTMINSTER, LONDON,

ENGLAND.

TAIL SKID FOR AIRCRAFT.

application medi June a1, 192i. serial no. matos.

(GRANTED UNDER 2 PROVISIONS 0F THE ACT 0F MARCHE, 1921, l1 STAT. I..,1313.)

To all whom it may concern:

Be it known that we, REGINALD KER- sHAw PrrnsoN and THOMAS SMITH DUNCAN, both subjects of the King of Great Britain, residing at Vickers House, Broadway, Westminster, in the county of ,London,`England, have invented certain new and useful lmprovements in or Relating to rll`ail Skids for Aircraft (for which we have filed an application in England No. 9,68%, April 6, 1920), of which the following is a specification.

This invention relates to tail skids tor l aircraft such as dying boats or hydroaeroplanes, the improved tail skid being more particularly intended for dying boats which are provided with landing gear for enabling them to alight on or start from the ground when desired.

According to this invention the tail skid is combined with orfforms part cfa rudder which is used forfsteering the iyino' boat when travelling in the water. rl`he tai skid, which may be in the form of a pivoted shoe, may have secured thereto acasing-which forms the water rudder and also constitutes a housing for ashock absorber with which the tail skid cooperates. The tail skid, the shock absorber and the water rudder constitute a compact unit which may be re= siliently connected to the means for moving the air rudder of the iying boat so that the air rudder and water. rudder can be moved simultaneously when `steering the dyingv boat. Y

ln order that the said invention may be lclearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawings, in which Y' Figure 1 is a side view partly in section of one construction of the combined tail skid and water rudder itted to a flying boat hull only a small part of which latter is illustrated.

Figure 2 is a plan view showing more particularly the shape of the water rudder. Figure 3 is an enlarged detail view of part of the shock absorber.

Figure A is -a small diagrammatic view showing the connection of the combined skid and water rudder to the rudder bar which controls the air rudder. 'l

A is the tail skid which s in the form of a shoe having .a suitable surface and shape for contacting with the ground. A is a sho-rt tubular rod to the lower end of which the aforesaid skid or shoe A is secured, the upper end of this rod being pivotally connected to the lower end of a vertical rod B by mea-nsv of flat interitting'lugs on the two rods'A and B and a horizontal pivot pin B". rFhe'rod B is mounted in bearings or supports B secured to the hull structure C in such manner as to be angularly movable on a vertical axis within a casing or sleeve B3 which is secured tothe hull and is carried to a point well above the waterline, thus obviating the necessity for a gland. By reason of the above construction the skid A is capable of angular movement around a vertical axis as may be required when the flying boat is traveling 4along the ground and also of angular movement on a horizontal Iaxis on the pivot pin B when it cooperates with a shock absorber as hereinafter described. Secured to the tail skid A and to the rod A is a rearwardlyv extending casing D which constitutes the main or lower part of the water rudder and which as shown is yassociated with an upper casing D secured to the angularly movable rod D. rlhe lower casing D normally projects slightly into the upper casing D but is adapted'to move to a substantial extent into the latter as shown in dotted lines in Figure l when the skid is moved upwardly the outer or rear part of the lower casing D being rounded as sho-wn to permit movement of the same into the upper casing D The two casings D and D constitute the water rudder and can be moved together as a whole around a vertical axis `when the rod B is angularly moved for steering the dying boat in the water. rlhis movement is generally eected simultaneously with the angular movement of the air rudder Dx (see Figure ll) for which purpose the rod. B may be suitably connected to the rudder bai' Dt by cables B5 having spring, compensators es A B5 toabsorb shocks when the aircraft isy As shown in'Figure 2 the two casings tion so as to offer minim/um resistance .when

in theJ water and during Hight, and this formation also enables the shock absorber to be conveniently housed within the two casings. The shock absorber may be of any suitable or known type, and in the example shown the shock absorber is of the Oleo type and comprises a cylinder E pivotally connected at its upper end to a pin F carried by a bracket F which is pinned or otherwise secured to the angularly movable rod B. The cylinder E contains a piston 4E fitting closely therein and having a plunger-like extension or .lower which passes through thelower end of the cylinderl E Aand which 'is surrounded by suitable packing rings E2. The lower eX- tremity ofthe p-iston extension is pivotally connected fo the tail skid as shown at E3; thus the shockabsorber is capable of being moved with the combined tail skid andthe from the lower the return rudder when the latter/is angularly adjusted by the angular movement of the rod B. l/Vhen the tail skid comes into contact with the ground and is moved upwardly the shock is absorbed by the resiliency afforded by the compression of air within the cylinder E due to the upward movement of the piston which as shown'is provided with a diaphragm E4 separating the space in the cylinder above the piston from the space in the piston extension. rlhese two spaces however are in communication by means of a tube E5 open at both ends and extending part of the piston extension through the diaphragm E4 to a point slightly above the piston E. A small quantity of oil is contained in the cylinder above the piston and during the upward stroke of the piston the compression ofthe air in the cylinder forces the oil through small aperture E6 in the piston into Ian annular space between the piston extension and the cylinder wall as shown in Figure 3; on the return movement of the piston due to eX- pansion of air in the cylinder the oil is gradually forced by the piston from the said annular space back'into the cylinder through the aforesaid apertures E6 thereby causing theI return movement of the piston tol be retarded. The piston extension also contains a small quantity ofoilwhich during movement ofthe piston is forced by Ithe expansion of the Vair in the piston extension upwardly through the tube E5 into the space in the cylinder E above the piston thus replenishing any leakage of the oil in the cylinder. The level of the oil Aabove the piston is determined by the height of the aforesaid tube E5 so tha-tally excess of oil forced into the cylinder from the piston extension is automatically returned by over-flowing through the tube E5 back into the piston extension. The main use of the tube E5 is to enable the piston,w extension to serve as an additional air chamber, as

part of reduced diameter without this tube the said extension would vmerely contain useless oil.

`What we claim and desire Letters Patent of the United l. A combined tail skid and Water rudder forrhydro-aeroplanes or flying boats, comprising a pivoted skid member having an extension, which constitutes the rudder or the main portion thereof.

2. A combined tail skid and water rudder for hydro-aeroplanesor flying boats, comprising a movable skid rudder portion provided on said skid member, and adapted to be moved relatively to another rudder portion, which forms an extension of the rudder portion on the skid so that two rudder port-ions form a water 'rudder of large area.,

3. A combined tail skid and water .rudder for hydro-aeroplanes or flying boats, comprising a movable skid member, a rud- States is for hydro-aeroplanes or flying boats, com. prising an angularly movable rod, a skidmember pivoted on said rod, a rudder portion on said skid member, a rudder portion carriedon ,said angularly movable rod, a shock absorber contained in said rudder portions which are o-f stream line formation.

6 A combined tail skidand water rudder for hydro-aeroplanes or flying boats, =comprising a skid member having a rudder and movable in two directions and a shock ab- -sorber movable with said skid in one direction and adapted to absorb shocks when the skid ismoved in the other direction, said shock absorber comprising a cylinder with a piston therein,tlie latter having a hollow extension in communication in the air space above the piston by means of a tube ythrough which oil can be forced from into the cylinder above the piston.

7. .A combinedtail skid and water rudder for hydro-aeroplanes or flying boats, .comprising a movable skid member, Va rudder combined and movable therewith, and means whereby the skid member with the rudder can bemoved in unison with the air rudder of the flying boat.

8. A combined tail skid and water rudder fonhydro-aeroplanes or flying boats, commember, and ader portion thereon, adapted to co-operatethe extensionv to secure by Y Lavaca@ prising a vertical rod angularly movable in supports on the flying boat structure, a skid member pivoted at its forward end to said rod, a bracket fixed to and movable with said rod, a shock absorber interposed between the rear end of the skid member and thesaid bracket, a water rudder movable with said skid and means whereby the said rod is connected to the means for moving the air craft rudder so that the said rod with the skid, shock absorber and water rudder may be moved simultaneously with the air rudder.

9. A combined tail skid and water rudder for hydro-aeroplanes or flying boats, comprising a vertically disposed rod angularly movable in supports on the flying boat structure, a skid member pivoted at the lower end of said langularly movable rod, a bracket fixed to and movable with said rod, a shock absorber interposed between the said bracket and the rear end of the skid member, a casing ixed on and movable with said rod a casing fixed on and movable with said skid member and ada ted to fit into the upper casing, the two caslngs forming a water rudder of stream line forma-` yor move relativelyl tion land enclosing said shock absorber, and means connected to said rod and to the air rudder of the flying boat so that the skid member with the aforesaid shock absorber and water rudder can be moved simultaneously-with the air rudder.

10. A combined tail skid and water rudderV for aircraft comprising an angularly movable rod, a skid or shoe pivotally connected to the lower end thereof, a shock absorber interposed between said skid or shoe and a bracket on Said rod, and a casing secured to said skid and adapted to co-operate to an upper casing, the two casings constituting a housing for the shock absorber.

11. A combined tail skid and water rudder for aircraft comprising a skid bar' capable of angular movement in two directions, a two-part casing, one part of which moves in one direction with said skid bar wh'ilst the other Ipart moves in both directions, and a shoc absorber associated with said skid bar and housed in the said twopart casing.

RIEGINALD MAW NEON. THOMAS Sli'lll'll DUNCAN. 

